The present disclosure relates to an iso-grid composite component and more particularly to gas turbine engines having convergent/divergent nozzles with iso-grid composite components.
A variable area exhaust nozzle optimizes the thrust produced within a gas turbine engine. In augmented gas turbine engines, convergent/divergent (C/D) nozzles provide a multitude of nozzle positions. The term “convergent-divergent” describes an exhaust nozzle having a convergent section upstream of a divergent section. Exhaust gases exiting the turbine section pass through the decreasing diameter convergent section before passing through the increasing diameter divergent section.
The convergent section is pivotally connected to an exhaust duct structure and to the divergent section. The divergent section is pivotally connected to the convergent section and to an external fairing positioned radially outboard of the divergent section. The upstream end of the external fairing is pivotally attached to an outer static structure to provide an outer aerodynamic surface for the C/D. The convergent, divergent, and external fairing sections generally include flaps and seals to accommodate changes in the nozzle variable orifice area and axis skew (if the nozzle is vectorable) by sliding relative to and overlapping each other as the orifice area decreases or increases.
The flaps and seals are often manufactured of carbon fiber composites which incorporate either monocoque constructions (consistent thickness part) or hollow rib reinforcements. Although effective, these techniques may require significant weight or design space.